Gun



0. V. PAYNE.

GUN.

APPLICATION FILED DEc,20, I9I9.

Patented Nov. 22, 1921 En we?? P@ a @jaar 0. V. PAYNE.

GUN.

APPLICATIQN FILED Dic. 20, 1919.

Patented Nov. 22, 1921.

tra Ta a esta.

OSCAR V. PAYNE, OF CLEVELAND, OHIO, ASSIGNOR TO AUTO-ORDNANCE CORPORA- TION, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

GUN.

Specification if Letters Patent.

Patented Nov. 22, 1921.

Application filed December 20, 1919. Serial'No. 346,406.

To all whom t may concern:

Be it known that I OSCAR V. PAYNE, a citizen of the United States, and resident of Cleveland, in the county of Cuyahoga and State of Ohio, have invented new and useful Improvements in Guns, of which the following is a specification.

T his invention relates to automatic guns of the type disclosed in the vPatent to Blish 1,131,319, granted March 9, 1915, and in applications Serial No. 203,873, filed November 26, 1917, Serial No. 203,887, filed November 26, 1917, Serial No. 282,642, filed March 14, 1919, and Serial No. 308,223, filed July 2, 1919, viz., of the type having a breach lock provided with oblique locking surfaces so inclined to the line of breech pressure that the breech is held in closed position during high breech pressure but is automatically unlocked directly by the breech pressure after .the pressure has decreased to a relatively low value.

The object of the invention is to improve the construction and disposition of the breech lock in guns of the aforesaid type with a view to increase the strength and durability of the lock and associated parts, to insure uniform and unfailing action of the breech closure, to increase the effective bearing surfaces of the lock without substantially increasing the over-all dimensions of the parts, to reduce or eliminate the shearing stresses on the lock, to simplify the construction and reduce the cost of manufacture of guns of this type, and generally to improve the action of such guns.

For the purpose of illustrating my invention I have shown one concrete embodiment in the accompanying drawings, in which- Figure l is a vertical axial section, showing parts broken away and other parts in elevation Fig. 2 is a top plan;

Fig. 3 is a. transverse section on line 3 3 of Fig. 1;

Fig. 1 is a left side elevation of the breech unit, comprising the bolt, firing member and lock, removed from the gun;

Fig. 5 is a top plan of the same unit;

Fig. 6 is a front elevation-of the lock;

Fig. 7 is a rear elevation of the lock;

Fig. 8 is a section on line 8-8 of Fig. 6; and

Fig.

The

9 is a section on line 9-1-9 of Fig. 6. particular embodiment of the invention chosen for the purpose of illustration comprises a han-d machine gun having a receiver R, a barrel A threaded into the forward end of the receiver, a cooling tube T around the barrel, a frame F' slidably interlocked over the o en bottom of the receiver, a shoulder piece I and a hand gri Gr mounted on the frame F, a magazine detachably secured beneath the receiver by a catch C', a bolt B slidable in the receiver, a lock L interposed between shoulders or abutments on the bolt and receiver respectively, a firing member comprising two parts M and N hooked together a recoil spring S, a buffer U, and a sight The trigger mechanism carried by the frame F forms the subject matter of application Serial No. 297,282, filed May 15, 1919, and the `magazine M is claimed in application Serial No. 297,286, filed May 15, 1919.

The bolt is recessed on top to receive the firing member M and the recoil spring S as shown in Figs. 1, 3 and 5, the recess being wide throughout the rearward end of the bolt to receive the spring, and relatively narrow throughout the forward end to accommodate the firing member which is substantially flat throughout its entire length. The firing pin N is disposed in an axial opening in the forward end of the bolt and hooks under a shoulder on the member M at its rearward end. The rearward end of firing member M projects into the spring recess and the recoil spring abuts against the end of the firing member and not against the bolt, the pressure of the spring being transmitted to the bolt through the medium of the firing member and lock asfhereinafter described. An actuator t projects upwardly from the forward end of the member M through a slot 5 in the receiver to provide means for manually retracting the breech closure when desired. The member M is provided with a transverse slot 1 on its upper side to receive a portion of the lock as hereinafter described, the slot sloping forwardly from top to bottom.

The bolt B is provided on its opposite sides with oblique grooves 2 which extend from the top to the bottom of the bolt and which incline rearwardly from top to bottom. The grooves 2 are at least as deep as the side walls of the bolt so that the grooves 3 of the recess for 'the recoil spring. As shown in Figs. 2 and 5 the bolt is somewhat wider in the rear of the grooves 2 than in front thereof. v

The lock L comprises two legs 6 slidably fitting in the grooves 2 respectively on the opposite sides of the bolt and a body portion joining the legs together at thelr upper ends. The legs 6 are provided at their outer forward corners with tapering recesses 8 which form shoulders 9 sloping rearwardly from top to bottom at an angle to the vertical greater than the angle of the lugs` 6. The outer faces of the lugs 6 are flush with the sides of the wider portion of the bolt in the rear of the grooves 2 and the lateral faces of the recessed portions 8 are flush with the sides of the narrower portion of the bolt immediately in front of the grooves 2. The body 7 of the lock is provided with a bearing surface 10 parallel (or diverging somewhat from top to bottom) with respect to the shoulders 9, this bearing surface extending uninterruptedly throughout the full width of the lock. The lock also has transverse faces 11, 12, 13, and 14, face 11 being horizontal, face 12 being approximately perpendicular to face 10, face 13 sloping orwardly from top to bottom, face 14 being flush with the forward faces of legs 6, and face l5 being substantially per endicular to the plane of the bisector of t e angle between faces 10 and 14. The lock body v 7 is provided with a central slot 16 on its front and bottom to receive the firing member M and with a central shoulder 17 on the rear to bear against the rear face of slot 1 in the firing member, the slots 16 and shoulder 17 shaping the central portion of the lock body to fit slidingly in the slot in the firing member as shown in Fig. 1.

The receiver R is provided with' a transverse arched portion 18 to receive the upper portion of the lock, this arched portion being provided with a bearing plate 19, of bronze steel or other hard bearing material, against which the lock surface lO is adapted to abut, and with a surface 20 againstwhich the lock surface 12 is adapted to abut. The bearing plate 19 is dovetailed into the receiver at 21 and a pin 22, adapted to be inserted through an opening at one side of the receiver, is rovided to retain the plate in position. A ubricant duct 23 may lead inwardly from the side of the receiver and thence downwardly and forwardly through the plate 19 to the bearing surfaces between the lock and plate. The receiver is widened at 24 and 25 (Fig. 2) in lthe region of the lock to increase its stren h. In the rear of the line 27 (Fig. 1) t e receiver chamber is slightl wider thanthe widest portions ofA the bo t and lock to receive these portions with a free sliding fit. In front of the line 27 (Fig. 1) the receiver chamber is less wide by an amount-equal to the depths of the rel cesses 8 in fthe lock, l.thereby forming shoulders 28 and 29 (Fig. 2) in the plane of line 27 against which the shoulders 9 onthe lock are adapted to abut. The body of the bolt extends rearwardly to the plane of line 30 (Fig. 1), that is to the p'lane of the forward ends of the spring recess and the grooves 2, thereby having a bearing face in thls place adapted to abut against the face l@ o the lock throughout its entire width except at the central slot provided for firingr member M.

he operation of the breech closure is as i follows: when the gun is fired the breech pressure is transmitted throughl the bolt to the lock throughout the bearing surface 14 of the lock and thence to the receiver throughout the surface 10 of thelock which bears against the bearing plate 19.' The lock-receiver bearing (10) is inclined to the vertical at an an le somewhat greater than that of the boltock bearing (14), so that the lock constitutes a wedge, the difference between these an les bein sufficiently low to prevent the we ge lock rom being forced downwardly from between the bolt and receivei` duringx high breech pressure but being suiiclently igh to cause the lock to be forced down when the breech pressure has decreased to a relatively low value, according to the disclosures in the aforesaid patent and applications. When the lock moves downwardly out of locked position, the legs l 6 sl1de in the bolt grooves 2 and the central portion shown in section in Figs. 1 and 8 slides downwardly` into the recess 1 in the firing member. he downward movement of the lock is limited either by the lower ends of the legs enga ing against the bottom of the recelver or y the central portion engaglng the bottom lof the recess in the firm member. As the lock moves downwar yl the firing member is retracted relativel to the bolt and the bolt is retracted relatively to the receiver due to the obliquity of the abutting surfaces between the parts. After the lock has moved downwardly sufficiently to cle-ar the bearing plate 19 the bolt and lock and firing members move rearwardly as a unit, the surafce 11 of the lock sliding along the' upper surface of the receiver chamber. When the recoil spring returnsthe unit forwardly the inclined shoulders 9 on the lock engage the similarly inclined shoulders 28 and 29 on the receiver to c'am the lock upwardly into locked position. The recoil spring bears only against the rear end of the firing member so that its force is transmitted to the bolt through the medium of the lock; and owing to the reverse Obliquity of the engagingksurfaces between the firing member and loc the firing member also applies an upward component of force to the lock. The

reverse obli uity of the abutting surfaces between the ring member and lock is much less than the obliquity of the abuttingsurfaces betweenthe lock and bolt so that the firing member is advanced relatively to the' bolt during the final closing and locking movement of the bolt, firing the cartridge at the end of the forward stroke.

, From the foregoing it will be evident that the breech pressure is transmitted to the receiver through the transverse body portion 7 of the lock andlthat this portion of the lock is subjected to compression, only, there being no shearing or other stresses, 'the lock abutting faces of the bolt and receiver being substantially opposite along a line inclmed to the line of breech pressure. Moreover, the lock bears on the receiver throughout its entire width along a fiat surface of large area;

and at the same time the vertical movement of the lock in locking or unlocking is very short. Furthermore, the body of the lock bears against the bolt (surface 14) throughout the width of the lock except at the central slot 16. And the difference in bearing area between the surfaces 10 and 14 due to the slot 16 may be made sufficient to compensate for the greater pressure on surface 10 due to its greater Obliquity so that the pressure on the opposite sides of the lock may be made substantially equal per unlt area. In order properly to distribute the ressure over the surfaces 10 and 14 of the ock, these surfaces should be symmetrical with respect to a plane through the center of the body 7 perpendicular to the bisector of the angle between the surfaces. Thus in the illustration the surfaces 10 and 14 are symmetrical with respect to a plane (Fi 9) which intersects a plane y-y (whic makes equal angles with surfaces 10 and 14 or bisects the angle therebetween) along a line a which in turn is parallelto the plane of the upper surface of the breech block.

I claim:

1. A gun having a firing chamber and a bolt chamber, a bolt movable in the bolt chamber along a straight path substantially parallel with the axis of the firing chamber, the bolt and bolt chamber having opposed recesses extending substantially across one side of the bolt, and a lock movable between a position in the recesses where it engages the bolt recess along its forward side and the chamber recess along its rearward side, in which position it locks the bolt closed, and a position substantially within one recess, in which position the bolt is free to be retracted along said path, the lock abutting faces of the bolt and receiver being substantially opposite along a line inclined to the line of breech pressure.

2. A gun having a firing chamber and a' bolt chamber, a bolt movable in the bolt chamber along a stra-ight path substantially parallel with theaxis of the firing chamber,

the bolt and bolt chamber having opposed recesses extending substantially across one side of the bolt, and a lock movable between a position in the recesses where itv engages the bolt recess along its forward side and the chamber recess along its rearward side, in. which position it locks' the bolt closed, anda position substantially within one recess, in which position the bolt is free to be retracted along said path, the lockabutting faces of the bolt and receiver being substantially opposite, and the engaging surfaces between said lock and recesses being inclined to the line of breech pressure at such angles as automatically to unlock the bolt in response to the breech pressure acting thereon.

3. A gun comprising a receiver, a bolt reciprocatable' in the receiver, the receiver and bolt having opposed recesses extending transversely thereof, a bolt lock having a polygonal body disposedtransversely of the bolt and receiver, said body being adapted to abut against the faces of the bolt and receiver recesses respectively along surfaces substantially opposite to each other throughout substantially their entire abutting areas and to move substantially wholly into one of the recesses to permit the bolt to retract.

4. A gun comprising a receiver, a bolt vreciprocatable in the receiver, the receiver and bolt having `opposed recesses extending transversely thereof, a bolt lock having a polygonal body disposed transversely of the bolt and receiver, said body being adapted to abut against the faces of the bolt and receiver recesses respectively along surfaces substantially opposite to each other and to move substantially wholly into one of the recesses to permit the bolt to retract and the engaging surfaces between said lock and recesses being inclined to the line of breech pressure at such angles as automatically to unlock the bolt in response to the breech pressure acting thereon.

5. A gun comprising a receiver, a bolt reciprocatable in the receiver, the receiver and bolt having opposed recesses extending transversely thereof, a bolt lock having a polygonal body disposed transversely of the bolt and receiver, said body being adapted to abut against the faces of the bolt and receiver recesses respectively along surfaces substantially opposite to each other and to move substantially wholly into the bolt recess to permit the bolt to retract, and'said lock having a leg slidable in a guideway in the outside of the bolt.

6. A gun comprising a,receiver, a bolt reciprocatable in the receiver, the receiver and bolt having opposed recesses extending transversely thereof, a bolt lock having a polygonal body disposed transversely of the bolt and receiver, said body being adapted to abut against'the faces of the bolt and receiver recesses respectively along surfaces substantially opposite to each other and to move substantially wholly into the bolt recess to permit the bolt to retract, and said lock having legs slidable in grooves in opposite outer sides of the bolt respectively. I

7. A gun comprising a receiver, a bolt're'- ciprocatable in the receiver, the receiver and bolt having opposed recesses extending transversely thereof, a bolt lock having a polygonal body disposed -transversely of the bolt and receiver, said body being adapted to abut against the faces of the bolt and receiver recesses res ctively along surfaces substantially opposlte to each other throughout substantially their entire abuttin areas and to permit the bolt to retract, said lock being confined substantially to the transverse dimension of the bolt.

8. A gun comprising a receiver and a breech bolt having op osed bearing surfaces inclined to the line o breech pressure, said surfaces being respectively disposed substantially wholly on opposite sides of a plane parallel to said line, and being substantially symmetrical with respect to a plane which intersects, along aline parallel with said plane, a plane making equal angles with said surfaces, and a breech lock intercalated betweenfsaid surfaces to lock the bolt closed, said lock being movable to one side -of said plane to unlock the bolt.

9. A gun comprising a receiver and a breech bolt having opposed bearing surfaces inclined to the line of breech pressure,psaid surfaces being respectively disposed substantially Wholly on opposite sides of the plane of one side of the bolt and being substantially symmetrical with respect to a plane which intersects, along a -line a'rallel with said plane, a plane making equa angles with said surfaces, and a breech lock intercalated between said surfaces to lock the bolt closed, said lock being movable to one side of said plane to unlock the bolt.

10. A gun vcomprising a receiver, a breech boltslidable in the receiver," one side of the side of t e receiver a bolt bein disposed in uxta'position to one long a longitudinal plane, the receiver and bolt having opposed transverse recesses so inclined that the forward face of the bolt recessis disposed on one side of said plane'and the rearward face of the receiver recess is dis osed on the other side of said plane, and t e two faces are substantially op osite to each other throughout substantia l their entire operative areas, and a lock disposed between said faces to transmit the breech pressure to the receiver, said lock being movable to one side of said plane to unlock the bolt.

11. A gun comprising a receiver, a lbolt slidable in the receiver, the bolt and receiver having op osed locking abutments, a bolt lock mova le into and out of position between said abutments, the set of abutting surfaces between the lock. and. receiver abutment and the set of abutting surfaces between the lock and bolt abutment being inclined relatively to each other at such angles ythat the breech 'pressure tends to force the lock from between the abutments, and the lock being so intercalated between the abutments as to transmit the breech ressure from the bolt to the receiver essentlally by compression.

12. A gun comprising a receiver, a bolt slidable in the receiver, the bolt and receiver having opposed locking abutments, a bolt lock movable into and out of position between said abutments, the set of abutting surfaces between the lock and receiver abutment and the set of abutting surfaces between the lock and bolt abutment beinginclined relatively to each other at such'angles that the breech pressure acting through tfhe bolt forces the lock from between the abutments a predetermined interval aftr firing, and the lock being so intercalated between the abutments as to transmit the breech pressure from the bolt to the receiver essentially by compression.

Signed by me at Cleveland, Ohio, this 11th day of December, 1919. OSCAR V. PAYNE. 

